Definition of rhythmite in US English:

rhythmite

noun

Geology Physical Geography
  • Each of the repeated units in a sedimentary formation exhibiting a rhythmic structure; specifically such a unit (typically a pair of laminae) deposited in a single year; a varve.

Origin

1930s; earliest use found in American Journal of Science. From rhythm + -ite, after German Rhythmit.

Pronunciation

rhythmite

/ˈrɪðmʌɪt/